CN107884629A - A kind of antenna feeder formula tightens field device - Google Patents

Abstract

The invention discloses a kind of antenna feeder formula to tighten field device, and the device is mainly made up of Compact Range reflecting surface, adaptive location feed, laser tracker and microwave dark room.Compact Range reflecting surface is quadratic surface, and reflecting surface size increase causes reflecting surface two dimension bending amount of bias to add up and into quadratic power increase, will malformation and long-term creep caused by aggravation deadweight, the structural stability and type face precision of reflection surface system can be reduced.The antenna feeder formula that the present invention announces tightens field device, and formula structure of being lain after reflecting surface use, feed is laid out using antenna feeder formula, is advantageous to be lifted the structural stability and type face precision of ultra-large Compact Range reflection surface system, the plane wave mass in lifting Compact Range dead zone.

Description

A type of antenna feeder compact field device

technical field

The present invention relates to the technical field of compaction field, in particular to a highly stable antenna feeder type compaction field device, the overall structure adopts antenna feeder layout, the main purpose is to improve the stability of the structural system of the compaction field and reduce the ultra-large-scale compaction field Structural design and manufacturing are difficult, improving the plane wave quality and long-term stability of the quiet zone of ultra-large-scale compact fields, especially suitable for ultra-large compact fields with reflective surfaces exceeding 30m.

Background technique

With the large-scale and mass-produced large-scale electronic equipment, such as the installation and maintenance of full-scale aircraft and large-scale ship-borne phased array radar, the demand for precise measurement of full-scale radar target scattering and large-aperture antennas is becoming increasingly urgent. The traditional single-reflector compact field usually adopts a ground-fed offset feed layout, and the reflector is a forward-inclined or side-lying structure. The bending and offset cantilever length of the ultra-large-scale reflector with the quiet zone size exceeding 30m is nearly 8m. The forward tilting moment of the ground-fed layout reflector will reduce the stability of the structural system, which is not conducive to overcoming the short-term deformation of the back frame caused by its own weight and Long-term creep is not conducive to ensuring the mechanical precision of the reflector system and the plane wave performance in the quiet zone. In addition, the ultra-large-scale compact field will increase the difficulty and manufacturing cost of the overall positioning of the reflective surface and the feed source, and it will be difficult to deal with the non-uniform settlement of the concrete foundation caused by non-uniform load, which will further cause the feed source to irradiate the reflective surface of the compact field out of focus Causes the quality of the quiet zone to deteriorate.

Contents of the invention

The object of the present invention is to propose an antenna-feed type compact field device, the feed source adopts an antenna-feed layout to irradiate the reflective surface, and the compact field is a rear-lying type to reduce the influence of the self-weight of the reflective surface on the structural stability and surface accuracy. The tracker monitors the drift of the relative position between the feed source and the reflective surface in real time, and adaptively positions the feed source to adjust to the focus of the reflective surface.

The present invention adopts following technical scheme in order to achieve the above-mentioned purpose of the invention:

An antenna-fed compact field device, the compact field is mainly composed of a rear-lying reflector system, an antenna-feed source system, a laser tracking measurement system and a microwave anechoic chamber. On the surface, the emitted spherical wave is collimated and corrected into a plane wave. The installation structure of the feed source and the reflective surface and the non-uniform drift of the foundation are monitored in real time by laser tracking, and the optimal irradiation of the reflective surface is realized by adaptive compensation positioning.

Wherein, the antenna-fed compact field reflecting surface adopts a reclining structure, and the design of the back frame cantilever caused by the forward tilt bias of the ground-fed bias-feed compact field reflecting surface is improved to a lower support, and by moving the reflecting surface The center of gravity of the system overcomes the forward tilting moment caused by its own weight, thereby improving its structural stability.

Among them, the laser tracker monitors the relative position drift between the reflective surface and the feed source system in real time, and adaptively positions the feed source to achieve the best matching of the illuminated reflective surface, which is conducive to improving the stability of the compact field structure system. It is difficult to integrate the installation foundation of the feed source and the reflection surface of the above-mentioned antenna-feed compact field, and there are factors of non-uniform drift in the mutual position. The laser tracker is used to monitor the dynamic change of the geometric position in real time, and adaptively locate the focus of the feed source to the reflection surface .

Wherein, the edge of the mouth face design of the compact field reflective surface is not limited to a specific edge form of the reflective surface, including sawtooth or curl processing. In order to suppress the interference of edge diffraction to the quiet zone.

Among them, the antenna-fed compact field system is installed in a microwave anechoic chamber, and the absorbing materials on each wall are selected and optimized to achieve the best low background level.

Among them, the core function of the antenna-fed compact field system is to form a super-large-scale plane wave quiet zone, which is not limited to the specific application of electromagnetic radiation, scattering or other simulation measurements for specific purposes.

Principle of the present invention is as follows:

The antenna-fed compact field device of the present invention is based on the low-center-of-gravity design of the reflecting surface structure, which improves the stability of the ultra-large-scale compact field structure system, improves the surface accuracy of the precision reflecting surface system, and improves the plane wave quality in the quiet zone. The principle of the low center of gravity design is to offset the bending of the ultra-large-scale off-feed reflective surface, adopt a rear-lying layout, and optimize the main bearing force of the back frame from a forward-tilting cantilever type to a lower support structure, reducing the forward-tilting overturning moment generated by its own weight , improving the stability of the structural system. The precise matching and positioning between the antenna feed source and the reflective surface is monitored by laser tracking in real time, and forms a closed-loop system with the feed source adaptive positioning device to achieve the best matching irradiation of the antenna feed source and form a super-large-scale iso The quiet zone of a plane wave with equal amplitude.

The advantage of the present invention compared with prior art is:

(1) The present invention improves the structural stability of the compact field system, and is especially suitable for large or super large compact field darkroom systems. The invention overcomes the traditional ground-fed bias-fed compact field layout, and the super-large-scale reflective surface will cause a large overturning moment due to excessive forward tilt. Because the large-scale reflective surface bias feeds asymmetric layout, the increased reflective surface bending offset will exceed 8m, and the huge overturning moment formed by its own weight and offset will greatly reduce the stability of the structural system, and it needs to be compensated to offset its impact Design can also increase engineering difficulty and manufacturing costs.

(2) The self-adaptive feed source positioning system of the present invention monitors the relative position change of the reflective surface and the antenna feed source in real time through laser tracking, adaptively matches and locates the focal point of the reflective surface, and solves the difficulty in installing the structural foundation of the reflective surface and the feed source. Inhomogeneous settlement drift caused by integration.

Description of drawings

Figure 1 is a schematic side view of the antenna feeder compact field device;

Fig. 2 is a frontal view of the caliber surface of the compression field device;

Fig. 3 is a side view of the caliber surface of the compression field device and the quiet zone at the front, middle and rear;

Fig. 4 is the amplitude and phase distribution diagram (300MHz) of the horizontal line in the quiet zone in the compact field device;

Fig. 5 is a vertical line amplitude and phase distribution diagram (300MHz) in the quiet zone in the compact field device;

The meanings of reference signs in the figure are:

In Figure 1: 1 is the reflection surface of the single-reflector compact field, 2 is the feed source adaptive positioning device of the antenna type compact field, 3 is the feed source of the compact field, 4 is the back frame structure of the truss type compact field, and 5 is The laser tracker for measuring the relative position of the feed source and the reflecting surface, 6 is the ground of the microwave anechoic room, 7 is the equipment to be tested in the quiet area of the compact field, 8 is the back wall of the microwave anechoic room, and 9 is the ceiling of the microwave anechoic room where the antenna feed is installed, 10 is the front wall of the microwave darkroom.

Among Fig. 3: 101 is the reflective surface of the reclining compact field, 301 is the feed source of the antenna type compact field, and 11 is the quiet zone of the compact field.

Among Fig. 4 and Fig. 5: Phase is the phase (deg.) distribution of the quiet zone field, and Magnitude is the normalized amplitude (dB) distribution of the quiet zone field, and the working frequency is 300MHz, and the intercept lines are respectively located at the horizontal line of the central quiet zone ( x position[m]) and vertical lines (y position[m]).

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

A preferred embodiment of the present invention:

Antenna type compact field device as shown in Fig. 1, includes reflective surface 1 of single reflector compact field, feed source adaptive positioning device 2 of antenna type compact field, feed source 3 of compact field, truss type compact field back Frame structure 4. Laser tracker for measuring the relative position of feed source and reflecting surface 5. Floor of microwave anechoic chamber 6. Equipment to be tested in the quiet area of the compact field 7. Back wall of microwave anechoic chamber 8. Ceiling of microwave anechoic chamber with antenna feed source installed 9 and microwave darkroom front wall 10, wherein,

The reflective surface 1 of the compact field of the single reflector is fixed on the front wall 10 of the microwave anechoic chamber not far from the microwave anechoic chamber through the truss-type compact field back frame structure 4, so as to correct the excitation source wavefront and convert it into the desired plane wave wavefront, reflect The surface is fixed by lying back, and its focal point is located on the ceiling 9 of the microwave anechoic room where the antenna feed is installed.

The feed source 3 of the compact field is installed at the focal point of the reflection surface of the ceiling 9 of the darkroom, and is used to provide an initial wave source when the system finally forms a plane wave in the equivalent quiet zone. The single-reflector compact field system adopts an antenna-fed layout. The main purpose is to improve the stability of the compact field structure system, reduce the difficulty of designing and manufacturing the ultra-large-scale compact field structure, and improve the plane wave quality and long-term stability of the quiet zone of the ultra-large-scale compact field.

The laser tracker 5 for measuring the relative position of the feed source and the reflective surface is fixed on the ground of the darkroom. The laser tracker monitors the relative position drift between the reflective surface and the feed source system in real time, and adjusts the feed source in real time through the feed source adaptive positioning device. The focal point on the reflective surface improves the stability of the quiet zone performance in the tight field.

The walls, floors, and ceilings of the microwave anechoic chamber are all covered with absorbing materials, and the absorbing materials are selected and optimized in layout to achieve the best low background level.

The device under test 7 in the quiet zone of the compact field is located in the quiet zone of the compact field system, and the electromagnetic waves in this zone have the characteristics of plane waves and can be used for antenna/RCS testing.

The reflective surface 1 of the single-reflector compact field has a size of 60m wide, 35m high, focal length 65m, and a virtual apex elevation of 1.5m. The reflective surface 1 of the single-reflective compact field has 16 left and right serrations, 28 upper and lower teeth, and the length of the left and right teeth 3.2m, the length of upper and lower teeth is 3.2m. The minimum operating frequency is 300MHz. The electrical size of the reflector 1 of the single-reflector compact field is about 35 to 60 times the wavelength, and the length of the side teeth is 3.2 times the wavelength. The aperture size and the length of the edge serration meet the low-frequency limit requirements of the compact field.

The size of the darkroom where the compact field is installed is 75m wide x 40m high x 140m long. The center of the quiet zone is located at the height of the center of the darkroom. The quiet zone is 40m wide, 20m high and 40m long. The rate is about 60%. The front and last offset of the double curvature of the rotating paraboloid is as close as 8m. As shown in Figure 3, 101 is the rear-lying compact field reflector, 301 is the feed source of the antenna-type compact field, and 11 is the quiet zone of the compact field. The layout of the reflecting surface adopts a reclining structure, which is beneficial to improve the force condition and long-term stability of the reflector structural system.

The minimum operating frequency of the compact field in this example specification is 300MHz, and there is a possibility that the low frequency can be extended to 150MHz, but special treatment is required for the layout of the absorbing material in the mirror area of the feed source to suppress the interference of the mirror defocused beam on the main beam. Due to the limited performance of the absorbing material in the meter wave band, especially the double-station image beam excited by oblique large-angle incidence, even if the wall coverage absorbing treatment is still similar to that of an ideal metal plane, the mirror reflection forms a defocused irradiation on the reflective surface, resulting in When the plane wave angular spectrum cracks, an upward spectral component appears, which interferes with the normal beam in the quiet zone.

The maximum operating frequency of the compact field in this example specification is recommended to be 18GHz, which meets the test requirements of common microwave bands, and there is the possibility of high frequency extension to 40GHz, so the overall surface accuracy of the reflector structure system needs to reach 75 microns. The high-frequency performance mainly depends on the accuracy and stability of the reflector structure system, and the antenna-feed layout design is conducive to ensuring the high-frequency performance of the ultra-large-scale compact field system.

The parts not described in detail in the present invention belong to the well-known technology in the art.

Claims (6)

1. a kind of antenna feeder formula tightens field device, it is characterised in that：The device is mainly by Compact Range reflecting surface, adaptive location feed And microwave dark room composition, feed system is using formula reflecting surface of being lain after the layout irradiation of antenna feeder formula, the spherical wave collimation that will be sent For plane wave, feed tracks monitoring in real time with the non-homogeneous drift of reflecting surface mounting structure and basis by laser, by adaptive equalization Position to realize to the optimal irradiation of reflecting surface.

2. a kind of antenna feeder formula as claimed in claim 1 tightens field device, it is characterised in that：Described antenna feeder formula Compact Range reflection Face is lain formula structure after using, and the backrest cantilever design caused by ground is presented into the biasing of leaning forward of formula offset-fed Compact Range reflecting surface is improved as down Support, the center of gravity by moving down reflection surface system overcomes the torque that leaned forward caused by deadweight, so as to improve its structural stability.

3. a kind of antenna feeder formula as claimed in claim 1 tightens field device, it is characterised in that：Laser tracker monitors reflection in real time Face changes with the drift of feed system relative position, and adaptive location feed realizes that reflecting surface is irradiated in best match, is advantageous to be lifted The stability of Compact Range structural system.

4. a kind of antenna feeder formula as claimed in claim 1 tightens field device, it is characterised in that：Described antenna feeder formula tightens field system Edge treated, specific curling or sawtooth processing are not limited to, to suppress interference of the edge diffraction to dead zone.

5. a kind of antenna feeder formula as claimed in claim 1 tightens field device, it is characterised in that：Described antenna feeder formula tightens field system It is installed in microwave dark room, optimization of the absorbing material through type selecting with layout of each sidewalls, realizes optimal low ambient level.

6. a kind of antenna feeder formula as claimed in claim 1 tightens field device, it is characterised in that：Described antenna feeder formula tightens field system Core Feature is to form ultra-large plane wave dead zone, and the electromagnetic radiation, scattering or other emulation for being not limited to special-purpose are surveyed The concrete application of amount.